| /* |
| * Copyright 2021 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| @file:Suppress("DEPRECATION") |
| |
| package androidx.compose.foundation.text.selection |
| |
| import androidx.compose.runtime.Composable |
| import androidx.compose.runtime.CompositionLocalProvider |
| import androidx.compose.runtime.mutableStateOf |
| import androidx.compose.runtime.remember |
| import androidx.compose.ui.layout.Layout |
| import androidx.compose.ui.Modifier |
| import androidx.compose.ui.composed |
| import androidx.compose.ui.geometry.Offset |
| import androidx.compose.ui.gesture.DragObserver |
| import androidx.compose.ui.gesture.rawDragGestureFilter |
| import androidx.compose.ui.gesture.rawPressStartGestureFilter |
| import androidx.compose.ui.layout.onGloballyPositioned |
| import androidx.compose.ui.platform.SelectionTrackerAmbient |
| import kotlin.math.max |
| |
| @Composable |
| private fun Wrap(modifier: Modifier = Modifier, content: @Composable () -> Unit) { |
| Layout(content = content, modifier = modifier) { measurables, constraints -> |
| val placeables = measurables.map { measurable -> |
| measurable.measure(constraints) |
| } |
| |
| val width = placeables.fold(0) { maxWidth, placeable -> |
| max(maxWidth, (placeable.width)) |
| } |
| |
| val height = placeables.fold(0) { minWidth, placeable -> |
| max(minWidth, (placeable.height)) |
| } |
| |
| layout(width, height) { |
| placeables.forEach { placeable -> |
| placeable.place(0, 0) |
| } |
| } |
| } |
| } |
| |
| @Composable |
| fun DesktopSelectionContainer(content: @Composable () -> Unit) { |
| val selection = remember { mutableStateOf<Selection?>(null) } |
| DesktopSelectionContainer( |
| selection = selection.value, |
| onSelectionChange = { selection.value = it }, |
| content = content |
| ) |
| } |
| |
| private fun Modifier.selectionFilter(observer: DragObserver): Modifier = composed { |
| val glue = remember { DragGlue(observer) } |
| rawDragGestureFilter(glue, glue::started) |
| .rawPressStartGestureFilter(glue::startDrag, true) |
| } |
| |
| private class DragGlue(val observer: DragObserver) : DragObserver by observer { |
| var started = false |
| |
| fun startDrag(downPosition: Offset) { |
| started = true |
| observer.onStart(downPosition) |
| } |
| |
| override fun onStop(velocity: Offset) { |
| started = false |
| observer.onStop(velocity) |
| } |
| |
| override fun onCancel() { |
| started = false |
| observer.onCancel() |
| } |
| } |
| |
| @Composable |
| internal fun DesktopSelectionContainer( |
| selection: Selection?, |
| onSelectionChange: (Selection?) -> Unit, |
| content: @Composable () -> Unit |
| ) { |
| val registrarImpl = remember { SelectionRegistrarImpl() } |
| val manager = remember { DesktopSelectionManager(registrarImpl) } |
| |
| val selectionTracker = SelectionTrackerAmbient.current |
| |
| manager.onSelectionChange = { |
| selectionTracker.getSelectedText = { manager.getSelectedText() } |
| onSelectionChange(it) |
| } |
| manager.selection = selection |
| |
| val gestureModifiers = |
| Modifier.selectionFilter(manager.observer) |
| |
| val modifier = remember { |
| gestureModifiers.onGloballyPositioned { |
| manager.containerLayoutCoordinates = it |
| } |
| } |
| |
| CompositionLocalProvider(LocalSelectionRegistrar provides registrarImpl) { |
| Wrap(modifier) { |
| content() |
| } |
| } |
| } |